Baurhoo B, Ferket P R, Zhao X
McGill University, Department of Animal Science, Ste. Anne de Bellevue, H9X 3V9, Québec, Canada.
Poult Sci. 2009 Nov;88(11):2262-72. doi: 10.3382/ps.2008-00562.
The effects of 2 levels of mannanoligosaccharide (MOS) in feed were compared with antibiotic growth promoters on growth performance, intestinal morphology, cecal and litter microbial populations, and carcass parameters in broilers raised in a sanitary environment. Dietary treatments included: 1) antibiotic growth promoter-free diet (control), 2) VIRG (diet 1 + 16.5 mg/kg of virginiamycin), 3) BACT (diet 1 + 55 mg/kg of bacitracin), 4) LMOS (diet 1 + 0.2% MOS), and 5) HMOS (diet 1 + 0.5% MOS). Birds were randomly assigned to 3 replicate pens/treatment (n = 55/pen). Body weight and feed intake were recorded weekly throughout 38 d. At d 14, 24, and 34, a 1-cm segment of duodenum, jejunum, and ileum was used in morphological analysis (n = 9 birds/d per treatment). At the same bird ages, cecal contents were assayed for lactobacilli, bifidobacteria, Salmonella, Campylobacter, and Escherichia coli, whereas litter was analyzed for Salmonella, Campylobacter, and E. coli. Carcass yields (breast fillet and tenders, thigh, drumstick, and wing) were determined at d 38. Body weight, feed conversion, and carcass yields did not differ among treatments. In contrast to birds fed VIRG or BACT, LMOS and HMOS consistently increased (P < 0.05) villi height and goblet cell number per villus in all intestinal segments at d 24 and 34. Bifidobacteria concentrations were higher (P < 0.05) in LMOS- and HMOS-fed birds at all time points. Birds and litter from all treatments were free of Salmonella. At d 14 and 24, cecal E. coli and Campylobacter counts were not different among treatments. In comparison to birds fed control, at d 34, BACT, LMOS, and HMOS significantly reduced (P < 0.05) cecal E. coli concentrations, whereas Campylobacter counts were reduced (P < 0.05) by VIRG, BACT, and LMOS. Litter bacterial counts were not altered by dietary treatments. In conclusion, under conditions of this study, MOS conferred intestinal health benefits to chickens by improving its morphological development and microbial ecology. But, there were no additional benefits of the higher MOS dosage.
在卫生环境中饲养的肉鸡中，比较了饲料中2种水平的甘露寡糖（MOS）与抗生素生长促进剂对生长性能、肠道形态、盲肠和垫料微生物种群以及胴体参数的影响。日粮处理包括：1）无抗生素生长促进剂日粮（对照），2）VIRG（日粮1 + 16.5 mg/kg维吉尼亚霉素），3）BACT（日粮1 + 55 mg/kg杆菌肽），4）低剂量MOS（LMOS，日粮1 + 0.2% MOS），和5）高剂量MOS（HMOS，日粮1 + 0.5% MOS）。将鸡随机分配到每个处理3个重复栏中（每栏n = 55只）。在38天的试验期内每周记录体重和采食量。在第14、24和34天，取1 cm长的十二指肠、空肠和回肠段进行形态学分析（每个处理每天n = 9只鸡）。在相同鸡龄时，检测盲肠内容物中的乳酸杆菌、双歧杆菌、沙门氏菌、弯曲杆菌和大肠杆菌，同时分析垫料中的沙门氏菌、弯曲杆菌和大肠杆菌。在第38天测定胴体产量（胸肉和嫩肉、大腿、小腿和翅膀）。各处理间体重、饲料转化率和胴体产量没有差异。与饲喂VIRG或BACT的鸡相比，在第24和34天，LMOS和HMOS持续增加（P < 0.05）所有肠段的绒毛高度和每根绒毛的杯状细胞数量。在所有时间点，饲喂LMOS和HMOS的鸡中双歧杆菌浓度更高（P < 0.05）。所有处理的鸡和垫料均未检出沙门氏菌。在第14和24天，各处理间盲肠大肠杆菌和弯曲杆菌数量没有差异。与饲喂对照日粮的鸡相比，在第34天，BACT、LMOS和HMOS显著降低（P < 0.05）盲肠大肠杆菌浓度，而VIRG、BACT和LMOS降低（P < 0.05）弯曲杆菌数量。日粮处理对垫料细菌数量没有影响。总之，在本研究条件下，MOS通过改善肠道形态发育和微生物生态对鸡的肠道健康有益。但是，较高剂量的MOS没有额外益处。
